Some Masks are Found to Generate Far Reaching Leakage Jets

Viruses Spread Through the Air on Dust and Fibers

Quantum Filtration Face Mask is Said to be More Efficient than an N95

New Developments for the “Mask Age”

Model Predicts Infection Risk in Any Situation

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Some Masks are Found to Generate Far Reaching Leakage Jets

A team of engineers from Heriot-Watt University, the University of Edinburgh and NHS Lothian clinicians tested the effectiveness of seven types of face covering—including medical-grade and home-made masks—found that they could all potentially help limit the spread of COVID-19.

However, some of the masks enabled strong jets of air to escape from the back and sides

Surgical masks and the tested hand-made masks were found to limit the forward flow of expelled breath, but also generate far-reaching leakage jets to the side, behind, above and below. Heavy breathing and coughing, in particular, were shown to generate intense backward jets.

Only masks that form a tight seal with the face were found to prevent the escape of virus-laden fluid particles, the team says.

https://medicalxpress.com/news/2020-05-covid-transmission.html

 

Viruses Spread Through the Air on Dust and Fibers

Influenza viruses can spread through the air on dust, fibers and other microscopic particles, according to new research from the University of California, Davis and the Icahn School of Medicine at Mt. Sinai. The findings, with obvious implications for coronavirus transmission as well as influenza, are published August 18 in Nature Communications.

"It's really shocking to most virologists and epidemiologists that airborne dust, rather than expiratory droplets, can carry influenza virus capable of infecting animals," said Professor William Ristenpart of the UC Davis Department of Chemical Engineering, who helped lead the research. "The implicit assumption is always that airborne transmission occurs because of respiratory droplets emitted by coughing, sneezing, or talking. Transmission via dust opens up whole new areas of investigation and has profound implications for how we interpret laboratory experiments as well as epidemiological investigations of outbreaks."

In the new study, UC Davis engineering graduate student Sima Asadi and Ristenpart teamed up with virologists led by Dr. Nicole Bouvier at Mt. Sinai to look at whether tiny, non-respiratory particles they call "aerosolized fomites" could carry influenza virus between guinea pigs.

Using an automated particle sizer to count airborne particles, they found that uninfected guinea pigs give off spikes of up to 1,000 particles per second as they move around the cage. Particles given off by the animals' breathing were at a constant, much lower rate.

Immune guinea pigs with influenza virus painted on their fur could transmit the virus through the air to other, susceptible guinea pigs, showing that the virus did not have to come directly from the respiratory tract to be infectious.

Finally, the researchers tested whether microscopic fibers from an inanimate object could carry infectious viruses. They treated paper facial tissues with influenza virus, let them dry out, then crumpled them in front of the automated particle sizer. Crumpling the tissues released up to 900 particles per second in a size range that could be inhaled, they found. They were also able to infect cells from these particles released from the virus-contaminated paper tissues.

https://medicalxpress.com/news/2020-08-airborne-viruses-non-respiratory-particles.html 

Quantum Filtration Face Mask is Said to be More Efficient than an N95

Reliable One Resources, Inc., a air and water filtration company, today announced results from testing of the world’s first 'block and kill" smart face mask, developed by its wholly-owned Quantum Filtration subsidiary, which helps protect the wearer from coronavirus and other infectious agents. The mask has undergone lengthy third-party laboratory testing, and the clinical data from one of the country's top testing laboratories shows that bacteria and viruses that come in contact with the mask are successfully killed and deactivated.  

The pores on the mask, which utilizes a proprietary graphene formula, are extremely small (in the nano range) averaging .0025 microns, yet the mask has a significantly higher breathability factor than other masks due to the large number of pores.  The superior blocking performance is possible due to a proprietary manufacturing process that fabricates the mask's fibers at 1/1000 the diameter of the fibers of today’s popular masks.  The pores are so small that no pathogen – not even the smallest virus – can penetrate the mask, as virus size ranges from .05 -.2 microns.  By comparison, an N95 mask is rated to block only 95% of particles sized .3 microns.

Quantum Filtration’s smart mask was designed to provide bacterial and viral protection for first responders, doctors, nurses, healthcare networks, military, workers in assisted living facilities, as well as protection from pollution, smog, diesel fumes and cigarette smoke, and suitable for protection from all particulates including airborne biohazards.

Quantum Filtration President Ken Wiedrich stated, “The reception for this mask has been exceptional thus far, and these test results validate our confidence in its potential.  Every physician and surgeon who has tried the mask has expressed that we may have cracked the code in the fight against the Covid-19 because the mask not only blocks all bacteria and viruses from entering a person's nose or mouth, but it also kills all bacteria and deactivates the viruses that come in contact with the mask. The breathability performance is also seen as a tremendous benefit. We see this mask as one of the best tools to change the way the world deals with the pandemic, save lives, and it even has the potential to spark the economy.”

 

New Developments for the “Mask Age”

A growing number of designers are betting that the world is entering “the mask age” People will routinely wear masks. They will want designs tailored to their needs.  Here are some covered  in an article by Yanko Design.

Masks can be made tighter fitting. The harness design is available on the Fix The Mask website as a free resource, to allow health professionals and regular citizens to get the most out of their face-gear while remaining safe from the virus.

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Designed by Japan-based Donut Robotics, the C-Face mask is a universal mask-cover that fits on top of your standard face mask. Switch it on, and the C-Face mask connects to your smartphone, giving you a wide variety of smart features. Not only does it enable you to answer calls and talk to people without holding your phone’s mouthpiece near your mouth, it auto converts speech to text, allowing you to reply to messages.

The Cannula mask by BDCI has a reinforcing endoskeleton. A thin plastic grille, this skeleton gives the mask its defining structure, preventing it from pressing against your face the same way a hanger prevents clothes from getting crushed by retaining its shape. Designed to be worn by people with respiratory difficulties, the endoskeleton even comes with a hollow spine that allows you to plug a nasal cannula to it, letting you direct fresh oxygen right to the wearer’s nose; effectively allowing them to inhale and exhale freely without worrying about a flimsy mask smothering them every time they try to breathe.

 

Inspired by the AIRPOP pollution masks, designer Oliver Perretta has created this trendy multifunctional mask. With usability being the keystone of any design, the mask not only filters the air but also acts as an air quality monitor. The quality monitor accurately transmits data to your smartphone, helping you be aware and keep yourself safe – whether you are navigating indoors or keeping yourself safe outdoors.

The UV Mask, unlike your conventional N95, doesn’t just trap microorganisms… it neutralizes them too, breaking down the genetic materials of coronavirus in milliseconds. Designed by UM Systems, the UV Mask comes with a dual filtration system that delivers the cleanest air quality of any existing face-mask. A preliminary replaceable N95 filter blocks 95% of particles like dust, dirt, debris, up to 0.3 microns. Microorganisms smaller than 0.3 microns then enter the UV-C Sterile Vortex, a helix-shaped filter that blasts microorganisms with UV-C light to destroy 99.9% of the remaining 5% on a DNA level, to give you air that isn’t just clean, it’s medical-grade, sterile-clean, bringing total filtration efficiency to 99.99%.

 

The full article is displayed at

  https://www.yankodesign.com/2020/08/13/face-masks-designed-for-a-sur

Model Predicts Infection Risk in Any Situation

Many of us face a constant barrage of decisions during this global pandemic: How dangerous is it to ride the bus? To teach and/or attend class? What’s my risk in a public demonstration?

University of Colorado Boulder atmospheric chemist Jose-Luis Jimenez has released a pilot tool that may help us answer some of these questions, or at least provide some informed guidance. 

The COVID Airborne Transmission Estimator is now publicly available online, said Jimenez, who is a CIRES Fellow and professor of chemistry at CU Boulder. It will be updated as more and more is understood about COVID-19 airborne transmission, and the tool is still somewhat tricky for a non-expert to use. But since Jimenez released the estimator Tuesday, he has been “bombarded with messages from people who want to use it or are already using it,” including people from other universities around the world. 

The Estimator calculates COVID-19 infection risk for a number of basic situations: college classrooms, choirs, taking a bus, being outdoors, participating in demonstrations. The model is downloadable and free, and users can tweak inputs to ask, for example, what’s my risk if other students wear or don’t wear masks? And can my choir sing together more safely by moving outdoors?

Jimenez is an expert in the chemistry and dynamics of particles in the air. He normally focuses on pollution particles, but for the last several months, he and many colleagues around the world have been focused on COVID-19 virus-containing particles, which spread through the air. He drew on those colleagues to informally review his Estimator, which is based on published methods and data. 

Though based on sound peer-reviewed science, the model itself has limited accuracy because it relies on numbers that are still uncertain: numbers that describe, for example, how many infectious viruses are emitted by an infected person, or just how efficiently homemade cloth masks prevent the virus from spreading from a wearer. On average, that’s probably 50 percent (cloth masks prevent half of all exhaled viruses from entering the air), but some masks fit poorly and others may fit better. 

“So we trust the order of magnitude of the results and especially the relative strengths of different actions such as increasing ventilation or wearing masks, but not the precise infection probabilities,” Jimenez said. “Different actions have very different costs, so the hope is that the tool can help allocate limited resources to reduce the risk of infection most effectively.”

For example, his base tool allows a user to ask about risk to a student if, say, a professor is infectious but still teaching, perhaps because she’s asymptomatic. The model estimates a 4% risk of infection in this situation, assuming 50 minutes inside a classroom under the socially-distanced conditions planned for Fall 2020 at CU Boulder (65 square feet per person). And it predicts risk to a professor and other students if one student in the room is infected: 0.5%. The difference is very real: A professor is generally speaking out loudly and nearly continuously, and loud speech emits more particles than simply sitting and breathing. But the precise numbers of 4% and 0.5% should be considered rough estimates that capture the general magnitude of risk. 

“The tool is helpful to run “what if” calculations, it’s a practical initial guide,” said Greg Blonder, an engineering professor at Boston University. “It’s too early to rely on for campus decision making, but it’s helpful to identify the most critical factors.”

Neal Langerman, a chemical safety consultant in California, called the new Estimator "a semi-quantitative understanding of risk of illness from various behaviors.

"And it’s much better than anything else we have out there," Langerman said. 

‘the model assumes cloth and surgical masks  would reduce virus emission by 50% compared to 90% for N95 masks

For virus inhalation the assumption is 30% for general masks including surgical masks worn by the public and 90% for the N95 mask

The model takes into account the infection rate in the population, air changes per hour in the pace, and length of time the risk taker is in the room.  Another variable is the activity of the emitter. In a classroom where a teacher would do most of the talking, the risk to others is higher  than if it is a student who is silent.

https://cires.colorado.edu/news/covid-19-airborne-transmission-tool-available